Regensburg 2010 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 9: Physics of Cells I

BP 9.8: Vortrag

Dienstag, 23. März 2010, 11:45–12:00, H43

The mechanical characteristics of embyronic stem cells influence their first fate decisions — •Kevin Chalut¹, Penelope Hayward², Franziska Lautenschlaeger¹, Chea Lim², Alfonso Martinez-Arias², and Jochen Guck¹ — ¹Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK — ²Department of Genetics, University of Cambridge, Cambridge, UK

The level of expression of the gene Nanog in embryonic stem (ES) cells defines their pluripotency: ES cells with a high expression of Nanog (HN) remain pluripotent while ES cells with a low expression of Nanog (LN) tend to differentiate. We used optical stretching and atomic force microscopy to explore the differences in mechanical phenotype between HN and LN embryonic stem cells. We found that LN cells are softer and more elastic than HN cells, while HN cells are highly plastic and maintain a high level of active response to forces in the environment. We will show that the highly active response of the HN cells is very robust, and has significant implications for sorting of ES cells in the embryo. Moreover, the high level of compliance of the LN cells compared to HN cells implies a susceptibility to physical cues in the environment that can steer the fate decisions of the ES cells. Finally, we present evidence that the actomyosin cytoskeleton network, which mediates the cells' active responses to their environment, fulfils an extremely important role in the fate decisions of ES cells, and in fact may define whether they maintain their pluripotent state or shift to lineage commitment.